The work of this group will concentrate on the spinal cord substantia gelatinosa and on the response of dorsal horn cells particularly to unmyelinated afferents in rats and cats. We will record afferent activity, dorsal root potentials, primary afferent depolarisation, single unit responses and the distribution and concentration of 11 peptides. We shall use electrical, mechanical and thermal stimuli including laser stimuli. The following manipulations will be added 1) lesions to peripheral nerves and to tracts in the cord. 2) The effect of neonatal and adult capsaicin given both systemically and locally. 3) The effect of various drugs including narcotics. The aim is 1) to study the connections between cells in laminae 1-5, 2) to define the response of cells with particular connections and containing particular peptides and responding to particular drugs.